Designed based on the Sentinel line of markers form Action Markers, the AM-4 offers players the same low weight and high durability. The extremely fast cycle rate of this marker also makes it a match for almost any electronically assisted marker.
The barrel shroud and CAR military-style shoulder stock give these markers a menacingly aggressive look that recreational and scenario players enjoy. Rubber wrap-around grips give this line a comfortable feel; a very important feature when crawling through mud and trees.
Sharing many features with the Sentinel line, the AM-4 also affords customers the opportunity to add their favorite accessories, like regulators and after-market barrels. The AM-4 also features Action Markers’ trademark Vari-Grip feed tube.
New and experienced scenario players will enjoy the quick-strip features and easy maintenance of the AM-4.

Armotech(Ariakon RIS) - Build Quality is infeior to that of the AM-4, but the cosmetics are superior. Performance surpasses the Araikon.
A-5 - Good Quality, GOod match, More of a Gas Hog, and a heavier investment when it comes to upgrades.

Definetly A Bolt, and if you're an accuracy freak then a barrel upgrade.

Strengths:

Durable. Asthetics. Consistancy. Accuracy, Superior Build Quality.

Weaknesses:

Bolt Needs To Be Upgraded, Stock Bolt Is Slightly Infeior.

Review:

I found this gun to be simply marvelous. It was all the bang for the buck I could have expected and more. I was happy with it from the get go, but after 10 games I decided it was time for some upgrades, since that time I have added the above. After the add-ons I could not be more pleased with this gun. It certainly outperfoms most other scenario guns. It Surpasses the quality of Armotechs in build quality, reliability, and ease of maintenance. Downsides are few and far between, but the ones that are there are a lack of field stripping capability, and a complex grouping of part types. A Angel Threaded Feed Neck. Autococker Threaded Barrel. Impulse Bolt. Tippman Buttstock (threading wise they match). Spyder Hammer. It is a marvelous compilation of strengths and parts and I could not be more pleased with it. Though I cannot complain about it in standard weather conditions, when the temperature dropped beloew 20 Degrees it's performance left a bit to be desired, the consitancy and gas usage dropped considerably, but other than that there are no complaints.

Conclusion:

A marvelous product, easy to upgrade, durable, reliable, amazing asthetics, and wonderful capabilties. I would consider this an intelligent buy.